Well bit



May 19, 1931. J. c. WRIGHT ET AL 1,805,898

WELL BIT Filed Oct. l, 1927 ing the invention;

'45 Fig. '6 is' a detailed Sectional View Patented May 19, 1931 UNITED `sf'rA-.Tlazs TION CALIFORNIA.

PATENT! OFFICE fj JESSE c. WEIGHT, F IIUNTINGEoN-PARK, AND' LYNE'F. BONNEY, 0F Los ANGELES, CALIFORNIA, AssIGNoRs To WIEMAN, KAMMEEEE, WEIGHT-V co.,v ING., A coEIoEA p WELL Erry yApplication viledctober 1, V1927. Serial No. 223,340.n v

This invention Vrelates toV a 'well drilling bit and hasgparticular reference to abit for use in drilling with the rotary method. f It is a general object ,of this invention to provide a simple, practicaljand improved well drilling bit of the type in which there is aleads ing cutting means Operableto form arcore and core removing means spaced above th cutting means to destroy the core.'

Our present invention has to` do with that general type of vbit set forth and claimed in our fcc-pending `applications, Serial No. 214,963 and 'Serial No. 21l,9ot,fpiled4 August A general objectofjthis linvention Vis to provide an improved and simplified construction and arrangement ofvpa'rts in a bit of the typeme'ntioned, y d 1- Another object of this inventionis to proa0 Vide' a simple Zand improved form of `Cutter for abit of the character mentioned. 4

- Itis afurther object of the present invention to provide .a'bit' ofl the ty-pe mentioned inv which theor-e'forming cutters and core i destroyingk cuttersv are' in the Y form of detachable units.` v f .The lvariousobjects and features yofthe invention will` be best and vmore fully understood from the followingl-detailed description lof two typical: applications of the invention, throughout which description reference is had to the accompanying drawings, in which# v Fig. 1 is a front elevation of a bit, embody- Fig..2 is an end view of the bit, being a viewtakenas indicated "by line 2]-,-2 on Fig,1; 1

Fig, 3 is a detailed sectional view taken vas indicated byline 3,-3 on Figl; Y

Fig. 4 is a detailed sectional view, taken indicated; by line 4 4 on Fig. f1; f J vFig.. 5 isa view similar to-.F-igfl s'how-fing another formofconstruction; and@ y taken as indicated by 'linej6-'6 .on Fig. 5.' l

Our v'nvention ,provides 4a bit-including, generally, a lbody 510, havingA spaced projefcf tions or legs 11, 'outer -cutters12 carriedby i theilegs to yprojectv downwardly therefrom and cut into the formationl to 'leave acore,

kand inner cutters 13 spaced above the cutters 12 operable to remove ork destroy the core. The body includes, generally, a shank 14 provided at its upper kend withV atapered screwthreaded pin projection..15..)Thefpin 15 is provided as a means for attaching'the bit to an operating member such, for `in-v stance, as astring ofdrill pipe; 1 Itis desiraf ble, in practice, to provide the shank 14 with aredu'ced part y1.6 toform a downwardly facing shoulder 17 that can be engaged by an overshot or over lishing tool in the event that vthe bitbecomes lost in the well; Y

The legsv 11 are integralwith the and extend downwardly and outwardlyffrom the lower end of the shank so that their outer ends are spaced a considerable distance beyon'd the lower end of the shank and are'outwardfof the shank. The legs are symmetrically disposed about the,k central axis fof the bit, it. beingpreferred` in practice to 4form the bit with two legs llflocatedvdiametrical ly opposite" each other,kk as shown ,in the drawings.k j V' Referring particularlyto Figs. 1' to -t'of ythe drawings, inclusive, each leg '1 1' extends or projects from the lower end portion of the shank sothat it hasfa substantially vertical forward side or front face 19. extending in a direction substantially parallelto aline Vshank -extending radially from the center of the i bit, a substantially vertical curved outer'end l wall 20 concentricwithuthe axis of thebit, and a bottom or lower face 21 that is inclined lto extend outwardly and downwardlyin thel ygeneral direction of the leg. The bodyorl main portion of the leg extends-'upwardly and Arearwardly fromk ther faces just describedand joins the shank. l

In the form yof theinventionunder consider'- ation,l eachcutterunit includes an outer' cutter 12 and an inner cutter 1,3. [The cutterV units ,such description Y apcutter jiinitfis may be Vcastings or forgingsy and, as they are Y .i

Au wardly the curvature of conguration of the outer end face 20 of the leg 11. The cutter 12, when in place, extends or protects downwardly from the outer end portion of the leg 11 so that it operates to make an annular cut in the formation being drilled, leaving a core in the center of the hole and cutting outward clearance for the leg 11. The cutter 12 is comparatively narrow and long and is arcuately curved so that its rear portion will followin the cut made by its forward portion.

The cutter 12 is made to extend or project downwardly from the leg 11 to make a fairly deep cut in the formation ahead of the leg and is provided at its lower end with'one has its various parts shaped so that it more or less closely or snugly receives the outer end portion of the leg 11. For instance, the socket has acurved part fitting the outer end face 21 of the leg and has an annularly disposed part fitting the bottom 21 of the leg. In the referred form of thek invention a lug 2,5 is

ormed on the cutter 12 in the socket 24 and a corresponding recess 26 is formed in the end face 2O of the leg to receive the lug. rlhe 'lug and recess co-operate to hold the cutter in place on the leg and to transmit driving strain from the leg to the cutter. We provide locking means forpositively retaining thecutter on the leg. In the drawings, we have shown a locking screw 27 extending through the upper portion of the cutter 12 and into the outer end portion of the leg 11. rllhe locking screw 27 may be held against working loose b means of a lock washeror any other suitaille device.

The innerr cutter 13 of the cutter unit is formed integral with the outer cutter 12 and is provided with a cutting edge 30 extending and inwardly from V the forward e ,ge or ace of thecutter 12 to the center of the bit. The cutter 13 has a. front part 3l which projects upwardly in front .of the front face 19 of the leg `to protect or shield the leg, and has a rearwardly extending bottom part 32 projecting under the bottom 21 of the leg 11' protecting the leg. The parts 31 and 32 of the cutter 13 forms'a structure L-shaped in cross section to receive the leg 11. In practice, a locking screw 35 is provided to extend'through the front part 31 of the, cutter 13 and into the front face 19 of the leg A11.

' The frontface 19 of the leg 11 is parallel with a line extending radially from the center of the bit and is offset rearwardly therefrom so that the cutting edge 30 of the cutter carried by the leg is or may be radial from the center of the bit.

The invention provides for the direction of circulating Huid to the cutting parts. For .this purpose, a circulation opening 36 extends downwardly into the shank 14 from its upper end and branch openings 37 are formed in the lower portion .of the shank or in the legs 11 to receive fluid from the opening 36 and discharge or direct it onto the cutters.

From the foregoing description of the general construction and arrangement of parts, it will be apparent how the cutters l2 operate to make a narrow annular cut in the formation being drilled, leaving a central core of the formation standing in the bottom ofthe hole. This core is cut away or broken down by the cutters 13 as the drill advances. It is to be noted that, the spaced leg construction, having cutter units operated by the legs, provides clearance around the various parts so that the cuttings are effectively carried away by the circulating fluid and are prevented from accumulating in a manner to cause the bit to ball up. The teeth of the cutters 12 are the only parts of the bit extending yinto completely confined formation and, in view of the fact that the cutters 12 are comparatively narrow,y this cut is made easily. The core left by the cutters 12, being unconlined, that is, being free in the hole, is readily cut away or destroyed by the cutters 13.

In the form of the invention illustrated in Figs. 5 and 6, twoV cutters 120 without core cutting blades, are applied to the ligs 11a of the body 10a, and a separate core cutter 50a is mounted at the lower end of the shank 14 between the legs 11a. The legs 11a are spaced a substantial distance apart and have parts extending straight down to carry the cutters 12a. In this case, the lower end of the shank 14 between thelegs 11a is formed with a recess 51 suitable for receiving the core cutter 50a. The core cutter 50a,-shown in the drawings, is in the form ofa plate mountg ed in the recess 51 by bolts 52 and having t a plurality of downwardly projecting cutting'teeth 35a. The teeth 3'5a'at the two sides of the central axis .of the tool are at different distances from the central axis so that they travel in different paths in a manner to completely cut away the core left by the cutters 12a. In .using this form of the invention, it will be obvious that the cutter 50a `may be provided with cutting parts of any suitable form. The core` cutter 50 is carried by the shank 14 between the legs V11 sol that Astrain is imparted ,from the cutter 50a directly to the shank, leaving the legs 11ul to withstand only the strains due tothe cutters 12a. T he cutters 12a are designed to fit over and` protect the legs 11a against Wear and are dressed to have cutting parts thatwill make the desired annular cut in the formation.

v It will be obvious that this form of the invention operates much the same as the other form, it being apparent how the cutters 12a operate to make an annular cut in the formation, leaving a core extending upwardly in 10 la manner to guide and steady the bit. The

core is destroyed or cut away by the cutter 50a as the bit advances. The bit provided by our invention is particularly eiiicient and effective as the outer. 15 cutters, which cut directly into solid confined formation, are comparatively small and make a comparatively narrow cut. The core left in the bottom of the hole by the outer cutters, being unsupported or unconlined, is readily cut away or broken down by the inner cutting means. Wel have found, in practice, that the core cutting means in our type of bit shows very little wear,thusindicating that the core left by the outer cutting means is very easily removed.

Having described only typical forms of our invention, we do not wish to limit ourselves to the specific details set forth, butwish to reserve to ourselves any changes or variations 3o that may appear to those skilled in the art or Y fall within the scope of the following claims.

i Having described our invention, we claim:

l. 'A well drilling bit including a body hav ing spaced oppositely disposed legs extending outwardly and downwardly from its lower end, a cutter unit carried by each leg, each unit including an outer cutter surrounding a portion of one leg and projecting downwardly from the outer end of the leg and an 40 inner cutter extending inwardly from the upper end portion of the outer cutter, the unit having a `lug extending into a recess in the le y 2. well drilling bit including, va body, spaced legs projecting from the body, cutter units mounted onvthe legs having sockets l receiving the lower end parts of the legs, andV lugs on the cutter units fitting recesses inthe` said end parts.

, 8. A well drillingbit including, a body,` v

spaced legs projecting from the body, cutter units Vmounted on the legs having sockets receiving the lower end parts of the legs, andV lugs on the cutter units'in the sockets extending into recesses in the said end parts.

In witness that we claim the foregoing we have hereunto subscribed our names this 12th day of September, 1927.

JESSE C. WRIGHT.

so LYNN F. BoNNEY. 

